Environment control system utilizing an electrochemical cell

ABSTRACT

An environment control system utilizes oxygen and humidity control devices that are coupled with an enclosure to independently control the oxygen concentration and the humidity level within the enclosure. An oxygen depletion device may be an oxygen depletion electrolyzer cell that reacts with oxygen within the cell and produces water through electrochemical reactions. A desiccating device may be g, a dehumidification electrolyzer cell, a desiccator, a membrane desiccator or a condenser. A controller may control the amount of voltage and/or current provided to the oxygen depletion electrolyzer cell and therefore the rate of oxygen reduction and may control the amount of voltage and/or current provided to the dehumidification electrolyzer cell and therefore the rate of humidity reduction. The oxygen level may be determined by the measurement of voltage and a limiting current of the oxygen depletion electrolyzer cell. The enclosure may be a food or artifact enclosure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/408,960, filed on Aug. 23, 2021 and currently pending, which is acontinuation of U.S. patent application Ser. No. 16/206,965, filed onNov. 30, 2018 and issued as U.S. Pat. No. 11,098,408 on Aug. 24, 2021,which is a continuation in part of International Patent Application no.PCT/US2016/063699, filed on Nov. 23, 2016 which claims the benefit ofU.S. provisional patent application No. 62/258,945, filed on Nov. 23,2015, U.S. provisional patent application No. 62/300,074, filed on Feb.26, 2016, U.S. provisional patent application No. 62/353,545, filed onJun. 22, 2016, U.S. provisional patent application No. 62/373,329, filedon Aug. 10, 2016 and U.S. provisional patent application No. 62/385,175,filed on Sep. 8, 2016, and this application claims the benefit ofpriority to U.S. provisional patent application 62/592,563, filed onNov. 30, 2017; the entirety of all application listed above are herebyincorporated by reference herein.

BACKGROUND OF THE INVENTION Background

There are many types of enclosures that require environment controlwherein the oxygen and/or the humidity level is controlled. For example,museum artifacts and documents are often stored in environmentallycontrolled enclosures to reduce degradation due to oxidation, rust andthe like. In addition, produce and other consumer products and goods maybenefit from storage in environment controlled enclosures, includingrefrigerated items. Electrolyzer cells utilizing membrane electrodeassemblies can be used in an electrolysis mode to reduce oxygen with anincrease in humidity, or decrease humidity with an increase in oxygen.In most enclosure applications for valuables and produce however, it isdesirable to reduce oxygen and also reduce humidity levels. There existsa need for an energy efficient, durable, quiet and effective environmentcontrol system for enclosures.

SUMMARY OF THE INVENTION

The invention is directed to an environment control system that employsan electrochemical cell(s) to effectively control oxygen and alsocontrol humidity within an enclosure. In one embodiment, oxygenconcentration is reduced and humidity is reduced within an enclosure. Inanother embodiment, oxygen concentration is increased while humidity isincreased. An exemplary environment control system utilizes oxygen andhumidity control devices that are coupled with an enclosure toindependently control the oxygen concentration and the humidity, RH,within the enclosure. An oxygen control device may be an oxygendepletion electrolyzer cell that reacts with oxygen and produces waterthrough electrochemical reactions. In an alternate embodiment, an oxygencontrol device is operated as an oxygen increase device, wherein oxygenis produced within the enclosure from the reaction with water to formoxygen and protons. A dehumidification device may be a dehumidificationelectrolyzer cell, a humidification electrolyzer cell, a desiccator, amembrane separator, and/or a condenser. A controller may control theamount of voltage and/or current provided to the oxygen depletionelectrolyzer cell and therefore the rate of oxygen reduction and maycontrol the amount of voltage and/or current provided to thedehumidification electrolyzer cell and therefore control the rate ofhumidity reduction.

In an exemplary embodiment, an environment control system is coupledwith an enclosure and comprises an oxygen depletion electrolyzer cellthat reduces the oxygen concentration in an enclosure. An oxygendepletion electrolyzer cell comprises an ion conducting material, suchas an ionomer that transports cations or protons from an anode and acathode, wherein the anode and cathode are configured on opposing sidesof the ionomer. The cathode is in fluid communication with the enclosureand a power source is coupled with the anode and cathode to provide anelectrical potential across the anode and the cathode to initiateelectrolysis of water. Water is reacted to form oxygen and protons onthe anode and the protons are transported across the ionomer, or cationconducting material, to the cathode where these protons react withoxygen at the cathode to form water, thereby depleting oxygen on thecathode side while producing water on the cathode side. As describedherein, novel system configurations are employed to reduce and controlthe humidity within the enclosure that may be produced, at least inpart, by the cathode of the oxygen depletion electrolyzer cell.

An exemplary environment control system may comprise an oxygen increaseelectrolyzer cell, wherein the anode is configured in fluidcommunication with the enclosure and produces oxygen from the reactionof water at the anode. An oxygen control electrolyzer cell may be run ineither an oxygen depletion mode or an oxygen increase mode, depending onthe potential applied across the anode and the cathode.

An exemplary environment control system comprises a humidificationcontrol device, such as a dehumidification device that reduces thehumidification level of the enclosure either directly or indirectly. Inan exemplary embodiment, the dehumidification device is adehumidification electrolyzer cell that pumps water out of the enclosureor out of a conditioner chamber, or the humidity control portion of theconditioner chamber. Other dehumidification devices include a separator,such as a separator membrane that allows moisture to pass therethrough,but is substantially air impermeable and therefore prevents oxygen flow.A separator that is substantially air impermeable has no bulk flow ofgas through the thickness of the separator and may have a GurleyDensometer time of 100 seconds or more, Model 4110N from GurleyPrecision Instruments, Troy NY, for example. Other dehumidificationdevices include desiccants, condensers and any combination of thedehumidification devices described.

An exemplary environmental control system comprises a humidificationelectrolyzer cell, wherein the electrolyzer cell is run with the cathodein fluid communication with the enclosure or with the humidity controlportion of a conditioning chamber. In one embodiment, a humidificationelectrolyzer cell produces moisture in a conditioner chamber and aseparator membrane transfers this moisture to an oxygen control chamber.

In an exemplary embodiment, the oxygen control and/or the humidificationelectrolyzer, comprises an ionomer, such as a perfluorosulfonic acidpolymer. The ionomer may be a composite comprising a support materialthat is coated and/or imbibed with the ionomer. The ionomer may be verythin, such as less than 25 microns, less than 20 microns and morepreferably less than 15 microns. A thin ionomer is preferred as it willallow for higher rates of proton transport and better efficiency.

In an exemplary embodiment, a conditioner chamber is utilized todehumidify gas that is introduce into the enclosure. A conditionerchamber, or portion thereof is in fluid communication with the enclosureand there may be one or more valves and/or fans or other air movingdevice to move gas between the conditioner chamber and the enclosure. Inan exemplary embodiment, a conditioner chamber is separated into anoxygen control chamber and a humidity control chamber. A separatormembrane may be configured between the oxygen control chamber and thehumidity control chamber and allow humidity to pass from one chamber tothe other. This separated conditioner chamber can effectively reducehumidity in the oxygen control chamber while simultaneously reducinghumidity in the oxygen control chamber. When the oxygen control chamberis at a higher humidity level than the humidity control chamber, watervapor will be transferred through the separator membrane to the humiditycontrol chamber, due to concentration gradients. The humidity controlchamber may reduce the humidity level through one or moredehumidification devices, as described herein. For example, adehumidification electrolyzer cell may pump water out of the humiditycontrol portion to maintain a very low level of humidity in the humiditycontrol chamber, and therefore draw moisture from the oxygen controlchamber through a separator. A separator may comprise an ionomermembrane and again, the ionomer membrane may be a reinforced ionomermembrane having a support material. A separator or moisture transmissionmaterial may be pleated or corrugated to provide a higher surface areaof the opening to the enclosure. An exemplary separator is an ionomer,such as Nafion® membrane, from E.I. DuPont, Inc, Wilmington, Delaware,or Gore-Select® membrane from W.L. Gore and Associates, Inc., Newark,Delaware.

An oxygen control chamber, or a portion thereof, may be configured as anexchange conduit having an inlet from the enclosure and an outlet backinto the enclosure. An exchange conduit may comprise a separator fortransfer of moisture from the oxygen control chamber or exchange conduitto the humidity control chamber. An exchange conduit may extend withinthe conditioner chamber or the humidity control portion of theconditioner chamber and may be nested, such as having additional lengthconfigured therein. An exchange conduit may be nested by having aserpentine configuration, a coiled configuration, a pleatedconfiguration and a hack and forth configuration. When a separator isconfigured on the exchange conduit, this nested configuration greatlyincrease the surface area for moisture transfer to the humidity controlchamber.

An exemplary environment control system may reduce humidity levels inthe humidity control chamber through one or more dehumidificationdevices, as described herein. A desiccant may be configured to absorbmoisture in the humidity control chamber and may be configured in adehumidification loop, a conduit with an inlet and outlet coupled withthe humidity control chamber. A fan or other air moving device may beused to force a flow of gas from the humidity control chamber throughthe humidity control chamber. In this way, moisture can be removedactively, by initiating the flow of humidity control chamber gas throughthe dehumidification loop, versus a passive dehumidification, wherein adesiccant is simply within the humidity control chamber. Any suitabledesiccant may be used including silica gel and the like. In addition, adesiccant or desiccator may comprise a heater to drive off absorbedmoisture and a set of valves may allow this expelled absorbed moistureto be expelled from the system, thereby rejuvenating the desiccant.

An exemplary environment control system may reduce humidity levels inthe humidity control chamber through a condenser. Again, a condenser maybe configured within the humidity control chamber or within adehumidification loop of the humidity control chamber. In addition, acondenser may produce condensed liquid water that can be expelled fromthe system through a valve or may be provided to a water chamber that isin fluid communication with the anode of the oxygen depletionelectrolyzer cell. The anode on the oxygen depletion electrolyzer cellreacts water to from oxygen and protons.

An exemplary environment control system may reduce humidity levels inthe humidity control chamber through a separator, such as an ionomermembrane separator, as described herein. The separator may be configuredbetween the humidity control chamber and the outside environment and maytransfer moisture from the humidity control chamber to the outsideenvironment when the humidity level within the humidity control chamberis greater than the humidity level in the outside ambient environment.

An exemplary environment control system may reduce humidity levels inthe humidity control chamber through a humidity control electrolyzercell having an anode in fluid communication with the interior volume ofthe humidity control chamber and a cathode exposed to the outsideambient environment. Water or humidity within the humidity controlchamber will react on the anode to form oxygen and protons. The protonsare transferred across or through the ionomer membrane and react withoxygen on the cathode to reform water. In addition, water molecules aredrug along with the flow of protons from the anode to the cathode. Acontrol system may monitor the humidity level within the humiditycontrol chamber, the oxygen control chamber and/or the enclosure andthen control the voltage potential across the anode and cathode of thedehumidification electrolyzer cell of the humidity control chamber.

An exemplary environment control system may comprise a fuel loop, or aconduit that directs gas from the humidity control chamber to the anodeside of the oxygen depletion electrolyzer cell and then back to thehumidity control chamber. A fuel loop reduces humidity in the humiditycontrol chamber by reaction of water in the fuel loop on the anode of anoxygen depletion electrolyzer cell and may be considered adehumidification device, as used herein. A fan and one of more valvesmay be used to provide a flow of gas from the humidity control chamberthrough the fuel loop and the anode on the oxygen depletion electrolyzercell may also receive gas or air from the ambient environment outside ofthe conditioner chamber.

A control system of an exemplary environment control system may compriseone or more sensors, such as an oxygen, humidity, and/or temperaturesensor that are configured in the conditioner chamber, the oxygencontrol chamber, the humidity control chamber and/or the enclosure orconduits to and from the enclosure. The control system may receive inputfrom these sensors and may then control the power level, voltagepotential and/or current to the electrolyzer cells to adjust thehumidity and/or oxygen levels as required. A user input feature may beused to set an oxygen and/or humidity level and/or limits for thesystem, such as for the enclosure and the control system, utilizing aprocessor or micro-processor may then control fans, valves, the powersupply to the electrolyzer cells and the like to maintain the user inputlevels or set points. In addition, data may be collected by the controlsystem and transferred to a secondary location. For example, a removablememory device, such as a thumb drive may be attached to the environmentcontrol system to collect data including sensed values of temperature,humidity levels, and oxygen concentration, as well as voltages appliedto the electrolyzer cell or cells and the like. The thumb drive could beremoved for download on a secondary electronic device or computer. Instill another embodiment, an exemplary environment control systemcomprises a wireless signal transmitter for transmitting the datawirelessly to a secondary location, such as a computer or server. Anexemplary environment control system may comprise a wireless signalreceiver for receiving set point values for temperature, humidity and/oroxygen concentration and may receive commands including voltagepotential inputs for an electrolyzer.

Any number of filters and/or valves may be used to control gas or airflow into or around the environment control system. Filters may beconfigured to the conditioner chamber to prevent contaminates frompoisoning the electrolyzer cells. Filters may be configured on inlet andoutlets to the enclosure. In addition, desiccators may be configured onair or gas inlets to the conditioner chamber, the oxygen control and/orhumidity control chambers.

In one embodiment, a fan is configured to produce a flow of process aironto an electrode of an electrolyzer. In an exemplary embodiment, amembrane electrode assembly (MEA) fan blows onto an electrode, whereinthe flow of air is substantially perpendicular, within about 30 degreesof perpendicular, or within about 20 degrees or more preferably withinabout 10 degrees of perpendicular to the plane of the electrode. It hasbeen found that this greatly increase the performance of theelectrolyzer. A fan blowing process air directly onto the anode of anelectrolyzer cell has been shown to increase the performance by morethan 200 percent. This force air flow onto the anode may remove boundarylayers that can reduce reaction rates.

There are many different applications wherein the control of oxygenconcentration and/or relative humidity levels, RH are required ordesired. Many enclosures are configured to control these environmentalparameters including, but not limited to, safes or enclosures forvaluable items that may be damaged by prolonged exposure to highhumidity, such as documents, artifacts, jewels, jewelry, weapons, guns,knives, currency and the like. In addition, there are applications wherea flow of air having a controlled level of oxygen and/or humidity aredesired, such as a Positive Airway Pressure, PAP, device, a respirator,an oxygen respirator and the like. A PAP device provides a pressurizedflow of air to a person to aid in effective breathing while sleeping. Anenvironment control system, as described herein, may provide additionalhumidity and/or oxygen to the flow of air in a PAP device. In addition,there are articles, such as produce, that may be located in an enclosurewherein the control of oxygen level is desired or beneficial. A reducedoxygen level in a refrigerator compartment for produce may prevent theproduce from spoiling or going bad. In addition, some enclosures mayhave a controlled and reduced level of oxygen to kill organisms.

An object of the present invention is to provide independent control ofoxygen concentration and humidity level within an enclosure utilizing atleast one electrolyzer cell. An exemplary object of this invention is toprovide oxygen depletion without an increase in relative humidity to anenclosure or a decrease humidity level of the enclosure. Anotherexemplary object of this invention is to provide an increased oxygen andhumidity level to an enclosure or air flow.

The present invention relates to electrolyzer technology with advancedpreserving capabilities for valuables, artifacts, or food items. Anexemplary electrolyzer cell is a polymer electrolyte membrane withcatalyst and current collectors on both sides with a housing. Anelectrolyzer cell is typically used while in contact with liquid waterto generate oxygen on the anode and hydrogen on the cathode. When usedin the open air with no available liquid water, they rely on theavailable water vapor or humidity in the air.

Oxygen reduction is very desirable to prevent oxidation, to kill germsand bug infestations, preserve food, valuable artifacts and to prevent afire from originating inside the enclosure. Separately, controlling thehumidity is just as important. There are disadvantages to running anelectrolyzer cell without independent control of the humidity and oxygenlevels. One is that you will likely reach 100% RH in an enclosure beforeremoving all of the oxygen. The other is the lack of precise independentcontrol over either of the conditions. The ideal humidity and oxygenlevel varies depending on what is being preserved inside the enclosure.One way to achieve precise control is to remove moisture separately withanother form of dehumidification or to use an electrolyzer cell inreverse while sealing it off from the enclosure. The seal could consistof a window with a membrane that allows moisture to pass through but notgases, including oxygen. This type of independent control of humidityand oxygen removal requires a way to measure the contents of theenclosure. You also need to be able to independently control thehumidifying and dehumidifying system with electronics. The integrity ofthe seal and the conditions outside the enclosure play a role in theefficiency.

An enclosure, as described herein, includes but is not limited tohumidors, refrigerator or freezer sub-compartments, museum displays, gunstorage, musical instrument storage, paper storage, and storage of ahost of moisture sensitive products such as fossils, ancient artifacts,stamps, bonds, etc. as well as shipping containers. An exemplary controlsystem may be sized to meet the demands of the enclosure. A largerenclosure will require a larger oxygen depletion electrolyzer cell areathan a smaller enclosure. An enclosure may be on the order of 0.1 m³ ormore, 0.5 m³ or more, 1 m³ or more, 5 m³ or more, 12 m³ or more or nomore than about 12 m 3 or no more than about 5 m³, no more than 3 m³ andany range between and including the volumes provided.

An exemplary environment control system, may comprise a remote monitorfor an enclosure, and may comprise wireless monitoring of the enclosureconditions including humidity level and oxygen concentration or level.The enclosure environmental conditions may be sent to a remoteelectronic device, such as a mobile telephone, tablet computer orcomputer. A user may change the desired set points of humidity,temperature and oxygen level of the enclosure. Wireless transmission mayalso allow a remote electronic device to record the enclosureparameters, temperature, humidity and oxygen level. In addition, a usermay receive an alert if there are significant changes in the enclosureenvironment parameters or if one of the parameters fall moves outside ofa threshold value for one of the set points.

There is recognition that in some cases reactant gases must be insidethe enclosure. The enclosure may not always be in a hermetically sealedsystem, i.e. some leakage in and out of the enclosure is an option. Inaddition, the system can be controlled with a sensor inside the device,in others the system is simply switched on and off for a limitedduration.

An exemplary control system comprises an oxygen and humidity controlsystem that can be used in combination with other systems. For example,it has been found that using Spanish cedar with a humidity controldevice provides humidity buffering. Also, it has been found that using asilica gel in combination with a humidity control device also provideshumidity buffering. And there are some advantages because if electricityis switched off, or if for some reason the system under or overhumidifies—the buffer can compensate. A silica gel or other hygroscopicmaterial may be placed within an enclosure to provide this moisturebuffering. Some hygroscopic materials have a humidity level rangewherein the absorb or release moisture when the RH goes above the rangeor drops below the range, respectively.

Utilizing electrolyzer technology in a cell to move moisture whilerelying on ambient air conditions can be challenging. The environmentproviding the moisture can be dry reducing the power output of the cellin either direction. There is also a reduction in performance when thissort of device is used in a cold environment like inside a refrigerator.Therefore, it is of the utmost importance to optimize the cell'selectrical contact characteristics with the catalyst. It is also anadvantage to heat the cell when in cold environments. In addition, thereis a significant advantage to adding air flow on the anode side of thecell in a unique way.

An important application of this technology is for use in medicaldevices such as CPAP's. Positive airway pressure (PAP) is a mode ofrespiratory ventilation used primarily in the treatment of sleep apnea.PAP ventilation is also commonly used for those who are critically illin hospital with respiratory failure, and in newborn infants (neonates).In these patients, PAP ventilation can prevent the need for trachealintubation, or allow earlier extubating. Sometimes patients withneuromuscular diseases use this variety of ventilation as well. CPAP isan acronym for “continuous positive airway pressure”,

A continuous positive airway pressure (CPAP) machine was initially usedmainly by patients for the treatment of sleep apnea at home, but now isin widespread use across intensive care units as a form of ventilation.Obstructive sleep apnea occurs when the upper airway becomes narrow asthe muscles relax naturally during sleep. This reduces oxygen in theblood and causes arousal from sleep. The CPAP machine stops thisphenomenon by delivering a stream of compressed air via a hose to anasal pillow, nose mask, full-face mask, or hybrid, splinting the airway(keeping it open under air pressure) so that unobstructed breathingbecomes possible, therefore reducing and/or preventing apneas andhypopneas. It is important to understand, however, that it is the airpressure, and not the movement of the air, that prevents the apneas.When the machine is turned on, but prior to the mask being placed on thehead, a flow of air comes through the mask. After the mask is placed onthe head, it is sealed to the face and the air stops flowing. At thispoint, it is only the air pressure that accomplishes the desired result.This has the additional benefit of reducing or eliminating the extremelyloud snoring that sometimes accompanies sleep apnea.

The CPAP machine blows air at a prescribed pressure (also called thetitrated pressure). The necessary pressure is usually determined by asleep physician after review of a study supervised by a sleep technicianduring an overnight study (polysomnography) in a sleep laboratory. Thetitrated pressure is the pressure of air at which most (if not all)apneas and hypopneas have been prevented, and it is usually measured incentimeters of water (cmH2O). The pressure required by most patientswith sleep apnea ranges between 6 and 14 cmH2O. A typical CPAP machinecan deliver pressures between 4 and 20 cmH2O. More specialized units candeliver pressures up to 25 or 30 cmH2O.

CPAP treatment can be highly effective in treatment of obstructive sleepapnea. For some patients, the improvement in the quality of sleep andquality of life due to CPAP treatment will be noticed after a singlenight's use. Often, the patient's sleep partner also benefits frommarkedly improved sleep quality, due to the amelioration of thepatient's loud snoring. Given that sleep apnea is a chronic health issuewhich commonly doesn't go away, ongoing care is usually needed tomaintain CPAP therapy.

An automatic positive airway pressure device, APAP, AutoPAP, AutoCPAP,automatically titrates, or tunes, the amount of pressure delivered tothe patient to the minimum required to maintain an unobstructed airwayon a breath-by-breath basis by measuring the resistance in the patient'sbreathing, thereby giving the patient the precise pressure required at agiven moment and avoiding the compromise of fixed pressure.

Bi-level positive airway pressure devices, BPAP, and variable positiveairway pressure devices, VPAP, provide two levels ofpressure:inspiratory positive airway pressure, IPAP, and a lowerexpiratory positive airway pressure, EPAP, for easier exhalation. Somepeople use the term BPAP to parallel the terms APAP and CPAP.) OftenBPAP is incorrectly referred to as “BiPAP”. However, BiPAP is the nameof a portable ventilator manufactured by Respironics Corporation; it isjust one of many ventilators that can deliver BPAP.

Expiratory positive airway pressure (Nasal EPAP) devices are used totreat primary snoring and obstructive sleep apnea (OSA). The device usedto treat primary snoring is an over-the-counter version while the devicefor OSA is stronger and requires a prescription. OSA is a seriouscondition with significant consequences when left untreated. Snoring,while not as significant as OSA, still disturbs sleep and can causepotential harm, over time, to the sufferer. Devices in this category arerelatively new and limited in number. Using the power of an individual'sown breath, these devices don't require electricity to function.Typically, they fit over an individual's nostrils and contain a smallvalve which opens as you breathe in and closes as you breathe out,creating gentle pressure to naturally keep the airway open and relievesnoring.

There are many optional features generally increase the likelihood ofPAP tolerance and compliance. One important feature is the use of ahumidifier. Humidifiers add moisture to low humidity air which canincrease patient comfort by eliminating the dryness of the compressedair. The temperature can usually be adjusted or turned off to act as apassive humidifier if desired. In general, a heated humidifier is eitherintegrated into the unit or has a separate power source.

Mask liners: Cloth-based mask liners may be used to prevent excess airleakage and to reduce skin irritation and dermatitis.

An exemplary environment control system may be integrated with any ofthe PAP devices described herein and can increase oxygen as well ascontrol humidity levels. In addition, an exemplary environment controldevice may be solid state and quiet, an important feature for a deviceutilized during sleep.

In an exemplary embodiment, a first electrochemical cell is configuredto consume oxygen within an enclosure or flow stream and will thereforeproduce moisture in the enclosure or flow stream. A secondary controldevice, such as an ERV may be used to separately control the humiditylevels. A second electrochemical cell may be coupled with the enclosureor flow stream and may be run in reverse of the first electrochemicalcell to remove moisture from the enclosure or flow stream. In anotherembodiment, a layer of a moisture transmission membrane or material isconfigured over an opening to the enclosure and may draw humidity fromthe enclosure when there is a differential in humidity levels, RH,between the interior of the enclosure and exterior of the enclosure orflow conduit. A moisture transmission material may be pleated orcorrugated to provide a higher surface area of the opening to theenclosure. An exemplary moisture transmission material is a ionomer,such as Nafion® membrane, from E.I. DuPont, Inc, Wilmington, Delaware,or Gore-Select® membrane from W.L. Gore and Associates, Inc., Newark,Delaware. In still another embodiment, a dehumidifier may be configuredwith the enclosure or flow stream to remove excess moisture produced bythe oxygen depleting electrochemical cell. This application incorporatesby reference, in their entirety, U.S. provisional patent applicationsNo. 62/353,545, filed on Jun. 22, 2016, application No. 62/258,945 filedon Nov. 23, 2015 and application No. 62/373,329 filed on August 2016.

This application incorporates by reference, in their entirety, thefollowing: U.S. provisional patent application No. 62/171,331, filed onJun. 5, 2015 and entitled Electrochemical Compressor Utilizing aPreheater; U.S. patent application Ser. No. 14/859,267, filed on Sep.19, 2015, entitled Electrochemical Compressor Based Heating Element andHybrid Hot Water Heater Employing Same; U.S. patent application Ser. No.13/899,909 filed on May 22, 2013, entitled Electrochemical CompressorBased Heating Element And Hybrid Hot Water Heater Employing Same; U.S.provisional patent application No. 61/688,785 filed on May 22, 2012 andentitled Electrochemical Compressor Based Heat Pump For a Hybrid HotWater Heater; U.S. patent application Ser. No. 14/303,335, filed on Jun.12, 2014, entitled Electrochemical Compressor and Refrigeration System;U.S. patent application Ser. No. 12/626,416, filed on Nov. 25, 2009,entitled Electrochemical Compressor and Refrigeration System now U.S.Pat. No. 8,769,972; and U.S. provisional patent application No.61/200,714, filed on Dec. 2, 2008 and entitled ElectrochemicalCompressor and Heat Pump System; the entirety of each relatedapplication is hereby incorporated by reference.

In an exemplary embodiment, an environment control system, as describedherein is used to reduce humidity in an enclosure. An enclosure for thereduction of humidity may include, but is not limited to, lightingenclosures such as automotive head lamps, vehicle electronic controlunits, compact photovoltaic arrays, cameras such as surveillancecameras, bar code scanners, battery packs, power control units, fluidreservoirs, charging stations, telecommunication devices, transformerunits, hard disk drives, artifact storage, gun storage, instrumentstorage, and the like. Water is reacted on the anode side of a membraneelectrode assembly to form oxygen and protons. The protons travelthrough the ionomer and reform water with oxygen on the cathode side.Humidity levels are therefore reduced in the enclosure. Water that isreforms on the cathode side can back diffuse through the ionomer to theanode side and decrease the efficiency of the system. Reducing backdiffusion may be accomplished by making a thicker ionomer, howeverionomer is expensive and this may be cost prohibitive. A discontinuousionomer membrane may be used having a gradient of properties through thethickness of the membrane from the cathode to the anode side. Adiscontinuous ionomer membrane, such as a sulfonated tetrafluoroethylenebased fluoropolymer, wherein the functional group is a perfluorosulfonylvinyl ether (PSVE), may have a gradient of equivalent weight through thethickness, wherein one portion of the membrane may have a low equivalentweight, such as about 800 to 1100 and another portion of the ionomermembrane may have a higher equivalent weight, such as above 1100, suchas about 1200 or more. The functional group may be sulfonic acid, (SO3H)or a carboxylic acid COOH. In an exemplary embodiment, a portion of adiscontinuous ionomer membrane has an equivalent weight of about 1500 ormore, or about 2000 or more. In an exemplary embodiment, a lowerequivalent weight ionomer is configured on the anode side and a higherequivalent weight ionomer is configured on the cathode side. In anexemplary embodiment, a higher equivalent weight ionomer is configuredbetween to lower equivalent weight ionomers, wherein the anode andcathode have lower equivalent weight ionomers. The higher equivalentweight ionomer between the two lower equivalent weight ionomers mayreduce back diffusion, at it may have less channels for water migration.In addition, a higher equivalent weight ionomer may create a highconcentration of ionomer on the cathode side of this higher equivalentweight ionomer, thereby reducing back diffusion to the anode frommoisture gradients. In an exemplary embodiment, a portion of adiscontinuous membrane has an equivalent weight that is at least about20% higher than another portion of the discontinuous membrane, or atleast about 30% higher, or at least about 50% higher. For example, aportion of the ionomer membrane, such as on the anode and cathode sidemay have an ionomer with an equivalent weight of about 1000 and acentral portion may have an equivalent weight of 1500 or more, therebybeing 50% higher than the anode and cathode ionomer portions.

The ionomer may comprise, consist essentially of or consist of StyreneEthylene Butylene Styrene (SEBS), polystyrene sulfonate (PSS),Styrene-Polyether ether ketone (S-PE) K), or may comprise apoly(arylene) back bone with functional groups of sulfonic acid, (SO3H)or a carboxylic acid COOH. Any combination of the ionomers listed may beused through the thickness of the ion exchange medium or layer to reduceback diffusion of water. For example, an exemplary ion exchange mediummay comprise perfluorosulfonyl vinyl ether with sulfonic acid functionalgroups on either surface, the anode and cathode side, and a layerbetween the comprises perfluorosulfonyl vinyl ether with carboxylicacid. In addition, the equivalent weight or concentration of functionalgroups may vary throughout the thickness. In another example, aperfluorosulfonyl vinyl ether ionomer with sulfonic acid functionalgroups may be configured on the anode side of the ion exchange mediumand a SEBS ionomer may be configured on the cathode side of the ionexchange medium. Again, any combination of ionomers may be utilized toprovide a reduced back diffusion of water into an enclosure.

The thickness of a discontinuous ionomer membrane layer may berelatively thin, such as less than 200 microns thick and preferably lessthan about 50 microns thick. A discontinuous portion, or portion thathas reduced back diffusion of water compared with the remaining portionof the ionomer membrane may be very thin, to reduce resistance of theprotons traveling from the anode to the cathode. The discontinuousportion, such as a portion with a higher equivalent weight, may have athickness of no more than about 20 microns, and preferably no more thanabout 10 microns or even no more than 5 microns. Again, thisdiscontinuous portion layer will reduce back diffusion and create a highlevel of moisture on the cathode side of this layer which will preventfurther back diffusion through the membrane.

In addition, a discontinued ionomer membrane may comprise a variation inionomer chemistry through the thickness of the ionomer membrane. A firsttype of ionomer may be use on the anode and/or cathode side and a secondtype of ionomer membrane may be use in a separate portion through thethickness. Again, a first type of ionomer may be used on the anode andcathode side with a separate type configured therebetween. Somealternative types of ionomer chemistry that may be used are described inU.S. patent application Ser. No. 15/800,259. This applicationincorporates by reference U.S. patent application Ser. No. 15/800,259,filed on Nov. 1, 2017, entitled Anionic Electrochemical Compressor andRefrigeration System Employing Same, which is a continuation in part ofU.S. patent application Ser. No. 15/448,734, filed on Mar. 3, 2017,entitled Anion Exchange Polymers and Anion Exchange MembranesIncorporating Same and currently pending, which claims the benefit ofpriority to U.S. provisional application No. 62/303,294, filed on Mar.3, 2016; U.S. patent application Ser. No. 15/800,259 also claims thebenefit of priority to U.S. provisional patent application No.62/416,141, filed on Nov. 1, 2016 and entitled Anionic Ionic ExchangeMembranes, and U.S. provisional patent application No. 62/430,833, filedon Dec. 6, 2016 and entitled Anionic Electrochemical Compressor andRefrigeration System; the entirety of all applications are herebyincorporated by reference herein.

An exemplary anion conducting polymer comprises quaternary ammonium orphosphonium functional groups, with poly(styrene), poly(phenylene), orpoly(arylene) backbones. Rigid, aromatic polymer backbones such aspoly(phenylene) or poly(arylene) provide high tensile strength alongwith resistance to chemical degradation via hydroxide eliminationreactions in a highly caustic environment. Ion exchange membranesproduced with these ionomers can further be reinforced by porous supportmaterials, such as microporous polytetrafluoroethylene, polyethylene, orpolypropylene membranes. Reinforcing the ionomer with the porous supportmatrix creates a composite anion exchange membrane. The preferredmicroporous support for use in the present invention is porousultra-high molecular weight polyethylene, as it has superior chemicalcompatibility (compared to expanded polytetrafluoroethylene, thestandard for reinforced cation exchange membranes) and porosity(compared to polypropylene, an alternative polyolefin support). Anexemplary ion exchange membrane for use in the present inventioncomprises a polymer with a poly(arylene) or poly(phenylene) backbone andalkyl or piperidine side chains featuring quaternary ammonium orphosphonium groups for ionic conductivity. In an exemplary embodiment, asolution of this ionomer is impregnated into a microporous polyolefinsupport for greater reinforcement and stability, especially at lowerthickness.

An exemplary anion conducting layer is a composite anion conductinglayer comprising an anion conducting polymer that is reinforced by asupport material. An even more desirable example of the presentinvention involves impregnating a microporous polyolefin supportmaterial between 5 and 50 microns, with porosity ranging fromapproximately 50% to 90% and pore size between approximately 20 nm and 1micron, with a polymer solution comprising a precursor form of theionomer comprising tertiary amine groups grafted to a poly(arylene) orpoly(phenylene) backbone, along with a crosslinking agent such asdivalent metal cations, tetramethyl-1,6-hexanediamine, or4,4′-trimethylenebis(1-methyl-piperidine), and then exposing the driedcomposite membrane to trimethylamine solution in water or ethanol. Thecrosslinking can be initiated or accelerated by exposure to hightemperatures as well as infrared or ultraviolet radiation.

An exemplary anion conducting layer is an anisotropic anion conductinglayer, that has varying properties through the thickness of the layer,and may comprise a series of thin films fused together to create ananisotropic membrane. Typically, quaternary ammonium ions are thecationic site and the backbone is varied, however it is possible tocreate cationic species with phosphonium as the cationic center. Thenumber of layers can be altered as well as step changes in the blendratio to generate membranes of significantly anisotropic internalstructures.

The anion conducting polymer within an anion conducting layer may becrosslinked using a crosslinking agent or compound. Anion conductingpolymers, such as within a composite anion conducting layer may becrosslinked to increase their mechanical and chemical stability,especially in hydrated conditions. In the case of an anionic ionomerwith functional quaternary ammonium groups, crosslinks may be madebetween polymer chains by linking quaternary ammonium groups togetherwith crosslinking agents such as polyamines, blocked polyamines,dicyanodiamides, divalent metal cations, tetramethyl-1,6-hexanediamine,4,4′-trimethylenebis(1-methyl-piperidine), or4,4′-(1,3-Propanediyl)bis(1-methyl-piperidine). A composite anionconducting layer may be formed by imbibing a support material with apolymer solution containing the ionomer along with one of the abovecrosslinking agents at a prescribed molar ratio of crosslinking agent tofunctional ionic groups. Any suitable anion conducting membrane may beused in the present invention. These membranes are characterized bynano-scale channels that essentially hold water and conduct anions (suchas hydroxyl ions). These new anion exchange membranes have demonstratedthe ability to achieve high conductivity for anions or highpermselectivity.

At the heart of an electrochemical compression is an ion-exchangemembrane with two catalytic electrodes. The entire assembly is referredto as a membrane-electrode assembly (MEA). Ion-exchange membranestransport ions across an ion conductive polymeric membrane, oftenreferred to as an ‘ionomer’. Ion-exchange membranes are made of apolymeric material attached to charged ion groups. Anion-exchangemembranes contain fixed cationic groups, such as ammonium orphosphonium, with mobile anions, which provide the ionic conductivity.Cation-exchange membranes contain fixed anionic groups, such ascarboxylic or sulfonic acid, with mobile cations, which provide theconductivity. The selectivity of the membranes is due to Domanequilibrium and Donnan exclusion and not due to physically blocking orelectrostatically excluding specific charged species.

Another way to reduce back diffusion is to drive moisture from thecathode. In an exemplary embodiment, an air moving device such as a fanis used to move moisture from the cathode thereby reducing the gradientof moisture from the anode to the cathode. Reducing the moisturegradient will reduce back diffusion. An air moving device may beconfigured to force or move air towards or away, or across the surfaceof the cathode and/or anode.

Back diffusion may also be a concern in systems where the oxygen levelwithin an enclosure is increased or decreased. In a system to increaseoxygen within an enclosure or on the anode side, the humidity isdecreased. This may not be preferred in some applications, such asPositive Airway Pressure, PAP, device applications, wherein an increasein oxygen is desired without a reduction in humidity levels. A thinionomer membrane that promotes back diffusion may be used in this case,wherein the membrane is less than 125 microns thick and preferably lessthan 50 microns thick and more preferably less than 25 or 20 micronsthick.

Operation of an environment control system to control humidity levelsmay be operated at voltages that are less than about 2.3V to avoid orreduce the production of hydrogen on the cathode, rather than water. Byturning down the voltage that is applied to the cell, little to nohydrogen is generated, and most of the energy put into the system isutilized to humidify the microclimate. Higher voltages have no issuesdehumidifying, the water is still being removed. But, the addition ofhydrogen has limited the use of electrochemical cells operating at 3Vfrom humidification applications.

An exemplary non-electrochemical humidity membrane assembly comprises amoisture transfer material configured between a non-electrochemicalanode and a non-electrochemical cathode. The moisture transfer materialmay be an ion exchange medium, membrane or layer as described herein ormay be a material with a high moisture transmission rate, such as aurethane or silicone for example. An exemplary moisture transfermaterial is substantially air impermeable and has no bulk flow of gasthrough the thickness as determined by a Gurley time of 100 seconds ormore using a Model 4110N Gurley Densometer or equivalent, from GurleyPrecision instruments, Troy NY, for example. Exemplarynon-electrochemical anodes and cathodes are electrically conductive andmay be heated by the flow of electrical current. An exemplarynon-electrochemical anode may be positioned in fluid communication withan enclosure and the non-electrochemical cathode may be positionedoutside of the enclosure. The cathode may be heated to a highertemperature than the anode which may drive moisture from the anode tothe cathode. The cathode may have a composition that causes it to heatto a higher temperature than the anode. For example, the anode maycomprise carbon or carbon and ionomer and the cathode may comprise aless conductive carbon or a carbon/polymer composite that is lessconductive and heats up more than the anode for the same amount ofelectrical current therethrough. The temperature gradient between thenanode and the cathode will promote the movement of moisture from theanode to the cathode. Also the higher temperature on the cathode sidewill reduce or prevent back diffusion of water that passes from theenclosure to the cathode. The anode or cathode may be configuredsubstantially over the entire surface of the anode or cathode, or aportion thereof, or may be configured in a pattern, such as a grippattern, wherein the electrical current applied can flow through thecontiguous pattern of the anode and cathode. The cathode may comprisecarbon or other conductive particles and a polymer, such asfluoropolytner which is hydrophobic and prevents retention of water onthe cathode. The use of a hydrophobic polymer with the conductiveparticles on the cathode may reduce back diffusion as the water may morereadily evaporate from the cathode surface. Carbon may be the conductiveparticle used in the composition of the anode and/or the cathode thecarbon may be, Ketjen black, such as ketjen black EC-300, or EC-600,Vulcan carbon such as XC-72, acetylene black, graphite, graphene oractivated carbon.

An exemplary proton conducting layer is based on an ion pair ionomer.This novel class of ionomers utilizes an anion exchange ionomerfunctionalized as previously described imbibed with an acidic group suchas phosphoric acid, carboxylic acid, and other acids known by thoseskilled in the art. The acid group can be adjusted to change theprotonic conductivity as well as the moisture transfer through themembrane. This layer may also be a composite layer with a poroussupport. This layer can also be used in conjunction with another ionomerlayer to tune the overall performance of the system.

The summary of the invention is provided as a general introduction tosome of the embodiments of the invention, and is not intended to belimiting. Additional example embodiments including variations andalternative configurations of the invention are provided herein.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 shows an exemplary electrochemical cell comprising a membraneelectrode assembly connected to a circuit for delivery of power from apower source, wherein electrolysis of water on the anode side producesprotons that are transported across the ion conducting membrane to thecathode side.

FIG. 2 shows an exemplary environment control system comprising anelectrochemical cell coupled with an enclosure.

FIG. 3 shows an exemplary environment control system configured at leastpartially within an enclosure.

FIG. 4 shows an exemplary environment control system comprising twoelectrolyzer cells coupled with an enclosure.

FIG. 5 shows an exemplary environment control system comprising twoelectrolyzer cells coupled with an enclosure with one of the cellshaving the anode in fluid communication with the enclosure and the othercell having the cathode in fluid communication with the enclosure.

FIG. 6 shows a diagram of an exemplary environment control system havinga separator to draw moisture from the oxygen control chamber.

FIG. 7 shows a diagram of an exemplary environment control system havingan exchange conduit through the conditioner chamber that exchangesmoisture through a separator.

FIG. 8 shows a diagram of an exemplary environment control system havinga serpentine exchange conduit through the conditioner chamber to enableeffective moisture transfer from the exchange conduit to the conditionerchamber.

FIG. 9 shows a diagram of an exemplary environment control system havinga recirculation loop between the conditioner chamber and the anode sideof oxygen depletion electrolyzer cell.

FIG. 10 shows a diagram of an exemplary environment control systemhaving a water chamber and an oxygen bleed valve.

FIG. 11 shows a diagram of an exemplary environment control systemhaving an enclosure filter, a conditioner chamber and inlet and outletfilters to the conditioner chamber.

FIG. 12 shows a front view of a safe having a lock on the front door.

FIG. 13 shows a back view of the safe shown in FIG. 12 with an exemplaryenvironment control system coupled to the back.

FIG. 14 shows a front view of a wine cooler having a front door to theinterior of the enclosure.

FIG. 15 shows a back view of the wine cooler shown in FIG. 14 with anexemplary environment control system coupled to the back.

FIG. 16 shows a front perspective view of a humidor having a door to theinterior of the enclosure on the top.

FIG. 17 shows a bottom perspective view of the humidor shown in FIG. 16with an exemplary environment control system coupled to the bottom.

FIG. 16 shows a bottom perspective view of the humidor shown in FIG. 15with an exemplary environment control system coupled to the bottom.

FIG. 18 shows a side view of an exemplary environment control systemconfigured to control the environment of growing enclosure, such as avase or pot for growing a plant.

FIG. 19 shows a perspective vie of an exemplary environment controlsystem having two electrolyzer cells for placement of an enclosurethereon.

FIG. 20 shows a person sleeping with the aid of a Positive AirwayPressure, PAP, device having an exemplary environment control system.

FIG. 21 shows a perspective exploded view of an exemplary electrolyzercell.

FIG. 22 shows a perspective view of an exemplary environment controldevice.

FIG. 23 shows a graph of an enclosure temperature and humidity with andwithout a fan blowing onto the cathode of a humidity controlelectrolyzer.

FIGS. 24 and 25 show a perspective view of an exemplary oxygen controlelectrolyzer cell configured with an MEA air moving device to produce aflow of process the anode of the membrane electrode assembly.

FIG. 26 shows an exemplary membrane electrode assembly having adiscontinuous ionomer membrane between the anode and cathode.

FIG. 27 shows an exemplary non-electrochemical humidity membraneassembly having an non-electrochemical anode and cathode separated by amoisture transfer material.

FIGS. 28 and 29 show the cathode side of an exemplarynon-electrochemical humidity membrane assembly having a discontinuousconductive pattern.

Corresponding reference characters indicate corresponding partsthroughout the several views of the figures. The figures represent anillustration of some of the embodiments of the present invention and arenot to be construed as limiting the scope of the invention in anymanner. Further, the figures are not necessarily to scale, some featuresmay be exaggerated to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Also, use of “a” or “an” are employed to describeelements and components described herein. This is done merely forconvenience and to give a general sense of the scope of the invention.This description should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Certain exemplary embodiments of the present invention are describedherein and are illustrated in the accompanying figures. The embodimentsdescribed are only for purposes of illustrating the present inventionand should not be interpreted as limiting the scope of the invention.Other embodiments of the invention, and certain modifications,combinations and improvements of the described embodiments, will occurto those skilled in the art and all such alternate embodiments,combinations, modifications, improvements are within the scope of thepresent invention.

FIG. 1 shows an exemplary environment control system 10 that utilizes anelectrochemical cell 12 comprising a membrane electrode assembly 30connected to a circuit 31 for delivery of power from a power source 87.The anode 20 of the MEA reacts with water to produce oxygen and protons.The protons H⁺ pass through proton conducting layer such as an ionomer,an example of an ion exchange medium 32, to the cathode 40. Water ispulled through the ionomer along with the protons. At the cathode, theprotons react with oxygen and produce water, thereby reducing the oxygenat the cathode and increasing water. The cathode is in fluidcommunication with the enclosure 50 and therefore reduces the oxygenconcentration and increases the moisture or RH of the enclosure. Theelectrochemical cell also includes a gas diffusion layer 39, a flowfield 38 and a current collector 33, configured on both the anode andcathode.

As shown in FIG. 2 , an exemplary electrochemical cell 12 utilizes a,membrane electrode assembly, MEA 12, connected to a circuit 31 forpower. As shown, this is an oxygen control electrolyzer cell 16 that isreducing oxygen concentration in the enclosure 50. An electricalpotential is created across the anode and cathode to initiate theelectrolysis of water on the anode 20, that produces oxygen and protonsthat are transported across the ion conducting media 32 or membrane, orionomer, to the cathode 40. A chamber is configured on the anode side 21for receiving incoming air and water moisture and a chamber or space onthe cathode side 41 is in fluid communication with an enclosure 50, suchas through one or more openings 51 into the enclosure. On the cathode,the protons are reacted with oxygen to produce water. Oxygen is depletedon the cathode side and water is produced. The protons also drag wateracross the ionomer from the anode side to the cathode side. On the anodeside, oxygen is produce and water is consumed in electrolysis reactionthat produces oxygen and protons. The membrane electrode assembly iscoupled between two electrical current collectors 33, or electricallyconductive layers, that provide the electrical power to the MEA. Anelectrical conductor plate, may be a screen or perforated metal and maybe the gas diffusion media and/or a flow field. A flow field 38 may havea plurality of channels for distributing gasses to the surface of theMEA or gas diffusion media. A gas diffusion media 39 may furtherdistribute gas to the anode and cathode. A sensor 82, such as a humiditysensor 83 and/or oxygen sensor 84, may be coupled with a control system80 for maintaining the humidity and/or oxygen level within the enclosureto a desired level. A user input 85 may be used to set a desired levelor range of humidity and/or oxygen concentration within the enclosureand a micro-processor 81 may control the power supply to theelectrochemical cell to keep the oxygen and humidity within the setpoints by the user. The electrochemical cell may be run in the oppositedirection, wherein the anode is in fluid communication with theenclosure and reduces moisture and increase oxygen concentration.

As shown in FIG. 3 , an exemplary environment control system 10comprises an electrochemical cell 12 at least partially configuredwithin the enclosure 50. As shown, this is an oxygen controlelectrolyzer cell 16 that is reducing oxygen concentration in theenclosure 50. In this embodiment, the MEA 30 may be run in a directionto produce moisture within the enclosure or to pump moisture out of theenclosure. An inlet/outlet conduit 25 on the anode side 21 extends outof the enclosure. Again, the electrochemical cell may be run to increaseor decrease the humidity and/or oxygen concentration within theenclosure. The cell can be operated to pump water into the enclosure oroperated to pump water out of the enclosure by changing the polarityacross the anode and cathode. The humidification control system mayprovide humid air to the enclosure by control of the circuit power todrive the electrolysis of water. A sensor 82, such as a humidity sensor83, monitors humidity and relays this measured value to the controllersystem 80. A processor 81 may control the amount of power, voltageand/or current to the MEA to control the amount of humid air provided tothe enclosure. A user interface 85, as shown by the up and down arrowsmay be used to adjust the humidity level within the enclosure. Thecathode side of the electrochemical cell is coupled with and enclosureand will reduce the oxygen level, while increasing the humidity level.

Referring now to FIGS. 4 and 5 , an exemplary environment control system10 comprises two electrochemical cells 12, 12′ in fluid communicationwith the enclosure 50. The two cells may be operated in the same mode,such as oxygen depletion and humidification mode, as shown in FIG. 4 ,wherein the cathode is in fluid communication with the enclosure,thereby increase the rate of oxygen reduction within the enclosure andhumidity increase within the enclosure. The two cells may also beoperated in an oxygen increase and humidity reduction mode, wherein theanode is in fluid communication with the enclosure, thereby increasingthe rate of oxygen increase and humidity reduction within the enclosure.Furthermore, the two electrochemical cells, may be operated in opposingmodes, as shown in FIG. 5 , wherein one electrochemical cell isconfigured to reduce oxygen concentration within the enclosure and oneis configured to increase oxygen within the enclosure. In this opposingoperation mode, the two cell may somewhat counteract each other and maybe less effective.

As shown in FIG. 6 , an exemplary environment control system 10 has twoelectrochemical cells 12, 12′ coupled with a conditioner chamber 62 anda separator 58 configured between the oxygen control chamber 60 and thehumidity control chamber 70. An oxygen control electrolyzer cell 16 hasthe anode cathode 40 in fluid communication with the oxygen controlchamber 60 and a humidity control electrolyzer cell 17 has the anode 20′in fluid communication with the humidity control chamber 70. Theseparator membrane, as described herein, allows moisture to betransferred between the oxygen and humidity control chambers, but limitsthe transfer of oxygen, since it is essentially air impermeable.Therefore, when there is a differential in humidity levels between theoxygen control chamber 60 and the humidity control chamber 70, humiditywill pass through the separator 58. The separator may be an ionomermembrane for example. The humidity control chamber 70 has the anode 20′of the second electrochemical cell 12′ in fluid communication to reducehumidity and increase oxygen concentration. This reduces humidity levelwill cause humidity from the oxygen control chamber 60 to pass throughthe separator and therefore reduce the humidity level in the oxygencontrol chamber. In this way, the oxygen control chamber nay have areduces oxygen concentration and a reduce humidity concentration, whichis desirable for many types of enclosures. A fan 97 may be configure tocontrol the flow from the oxygen control chamber to the enclosure 50,through the enclosure wall 55. An inlet exchange conduit 57 isconfigured with a filter 67 and the outlet exchange conduit 59 is alsoconfigured with a filter 69. A fan 97 or other air moving device isconfigured to force flow and exchange between the enclosure and theconditioner chamber 62, and specifically the oxygen control chamber 60.A fan and valve may be configured on the oxygen control chamber 60 orthe humidity control chamber 70 to allow exchange with the outsideenvironment. The concentration of humidity and/or oxygen may require anair exchange with the outside air, for example. A desiccant 90 andfilter 93 are configured to reduce the humidity concentration in thehumidity control chamber and may reduce the moisture from air beingdrawn into the humidity control chamber or may be configured in acirculation loop of the humidity control chamber, as shown in FIG. 8 ,for example. A desiccant may be replaced periodically as required by theapplication. A controller 80 may utilize inputs from sensors 83, 84 tocontrol the operation of the environment control system 10.

As shown in FIGS. 7 and 8 , an exemplary environment control system 10has an exchange conduit 61 as an oxygen control chamber 60 with an inlet57 and outlet 59. The exchange conduit 61 extends within the conditionerchamber, wherein at least a portion of the exchange conduit isconfigured with a separator 58 to allow moisture to pass from theexchange conduit, or oxygen control chamber, into the humidity controlchamber 70 portion of the conditioner chamber 62. In this embodiment,more surface area may be provided for the separator. In addition, thehumidity control chamber may be configured with a dehumidification loop91 that circulates gases from the humidity control chamber through adesiccator 90. A fan 97 is configured to move gasses through thedehumidification loop. As shown in FIG. 8 , the exchange conduit 61 isserpentine, to provide additional separator 58 exchange surface area.Again, any number of valves 98 and fans 97 may be used to exchangegasses within the chambers with the outside environment, as describedherein. A condenser 64 is also shown in the dehumidification loop. Acondenser and/or desiccant or desiccator may be configured in thedehumidification loop.

As shown in FIG. 9 , a portion of the humidity control chamber 70 gas isfed to the anode side of the electrochemical cell 12, an oxygen controlelectrolyzer cell 16 operating as an oxygen depletion electrolyzer cell.The oxygen depletion electrolyzer cell is configured with the cathode 40in fluid communication with the oxygen control chamber 60 and thehumidity control electrolyzer cell 17, acting as a humidity reductionelectrolyzer cell, is configured with the anode 20′ in fluidcommunication with the humidity control chamber 70. The humidity controlchamber may comprise moisture that can be consumed by the reaction atthe anode of the oxygen depletion electrolyzer cell, wherein water isconverted to oxygen and protons. A fuel loop 68 is configured to directhumidity control chamber gas to the anode of the oxygen depletionelectrolyzer cell. In this way, the moisture can be reduced in thehumidity control chamber 70 while providing the necessary fuel to theanode of the oxygen depletion electrolyzer cell. Again, any number ofvalves 98 and fans 97 may be used to exchange gasses within the chamberswith the outside environment, as described herein. A condenser 64 isalso shown in the dehumidification loop. A condenser and/or desiccant ordesiccator may be configured in the dehumidification loop.

As shown in FIG. 10 , an exemplary environment control system 10 has awater chamber 65 with a pervaporation layer 66 between the water chamberand the oxygen control electrolyzer cell. The pervaporation layer may bean ionomer membrane or any other material that allow water vapor totransfer through without any bulk flow of air, as described herein. Acondenser 64 is configured condense humidity into liquid water from theconditioner chamber 62. In this embodiment, a single electrochemicalcell 12 is utilized to reduce the oxygen concentration in the oxygencontrol chamber 60 of the conditioner chamber 62, which is in fluidcommunication with the enclosure 50 through the condenser. The condenseris configured to draw gas from the oxygen control chamber 60. In oneembodiment, there is no separator between the oxygen control chamber andthe humidity control chamber and the gas fed to the condenser is drawnfrom the conditioner chamber generally and the electrochemical cellreduces oxygen from this same conditioner cell. However, as shown, theoxygen control chamber is configured with an opening to the condenser, avalve 98 is shown here. The gas in the oxygen control chamber has areduced oxygen concentration and an increased humidity level, or watercontent. An oxygen bleed valve 99 may be configured to bleed the gasesfrom the oxygen control chamber or any portion of the conditionerchamber. Gas is drawn into the condenser and the water vapor iscondensed and collects in the bottom of the condenser, wherein it can befed to through a valve 73 to a water chamber 65, or fuel chamber for theoxygen control electrolyzer cell 16 acting as an oxygen depletionelectrolyzer cell. This may be a way of providing the water required tothe oxygen depletion electrolyzer cell, especially in arid environments.The pervaporation separator 66 keeps any contaminates in the water fromfouling or poisoning the catalyst of the anode. A valve may be openedwhen required to draw in more air to the cathode side of the oxygenreduction electrolyzer cell.

As shown in FIGS. 6 to 10 , a MEA air moving device 44 is configured toproduce a flow of process air, or forced air onto the anode of theoxygen control electrolyzer cell 16. The forced air may impinge directlyonto the anode as shown in FIGS. 6 to 9 or may flow across the MEA, asshown in FIG. 10 . As shown in FIGS. 6 to 9 an MEA air moving device 44is couple with the humidity control electrolyzer cell 17 and configuredto produce a flow of process air onto the anode of the humidity controlelectrolyzer cell. As described herein, the flow of process air onto theanode can greatly improve the performance of the cell.

As shown in FIG. 11 , an exemplary environment control system 10 has anenclosure filter 52 to the enclosure 50, and inlet and outlet filters tothe conditioner chamber 62. An activated carbon may be used in theenclosure filter to protect the MEA from contaminates inside theenclosure. The conditioner chamber may also comprise inlet and/or outletfilters to protect the MEA from contaminants from the ambient air. Thishumidification control system has a single electrochemical cell 12, ahumidification control electrochemical cell 17 that may be run with theanode or the cathode in fluid communication with the enclosure.Likewise, it may be an Oxygen control electrochemical cell.

As shown in FIGS. 12 and 13 , an exemplary environment control system 10is configured to control the environment within a safe 110. The front ofthe safe, as shown in FIG. 12 has a door 111 to form an enclosure 50.The environment control system 10 is configured on the back side of thesafe, as shown in FIG. 13 , and may control the level of oxygen and/orhumidity within the safe enclosure.

As shown in FIGS. 14 and 15 , an exemplary environment control system 10is configured to control the environment within a refrigerator 119, inthis a wine cooler. The front of the wine cooler, as shown in FIG. 14has a door 11 to form an enclosure 50. The environment control system 10is configured on the hack side of the wine cooler, as shown in FIG. 15 ,and may control the level of oxygen and/or humidity within therefrigerator.

As shown in FIGS. 16 and 17 , an exemplary environment control system 10is configured to control the environment within a humidor 114. The topof the humidor, as shown in FIG. 16 has a door 11 to form an enclosure50. The environment control system 10 is configured on the bottom of thehumidor, as shown in FIG. 17 , and may control the level of oxygenand/or humidity within the humidor enclosure.

As shown in FIG. 18 , an exemplary environment control system 10 isconfigured to control the environment of growing enclosure 117, such asa vase or pot for growing a plant. The environment control system 10 maycontrol the humidity and/or oxygen level of the space below the plant ordirt within the enclosure 50.

As shown in FIG. 19 , an exemplary environment control system 10 has twoelectrochemical cells 12,12′ for placement of an enclosure thereon.

FIG. 20 shows a person 101 sleeping with the aid of a Positive AirwayPressure (PAP) device 100. The PAP device or breathing device has a flowgenerator (PAP machine) 102 that provides the airflow to the hose 104that connects the patient interface 106. The hose connects the flowgenerator (sometimes via an in-line humidifier) to the interface 106. Aninterface includes, but is not limited to, a nasal or full face mask,nasal pillows, or less commonly a lip-seal mouthpiece, provides theconnection to the user's airway or respiratory system, such as throughthe nose or mouth. An exemplary environment control system 10 isattached to the flow generator 102 or enclosure of the flow generator 50and may be used to increase the level of oxygen and/or humidity withinthe pressurized flow delivered to the person. A PAP device, as usedherein, includes all of the variations of breathing aid devicesdescribed herein.

As shown in FIG. 21 , an exemplary electrolyzer cell comprises a filter94, MEA fan 44, housing components 43, 43′, flow fields 38, 38′, currentcollector 33, membrane electrode assembly 30, gas diffusion media 39,and a gasket 45. This assembly has a fan configured to blow air directlyonto the MEA 30. As described herein, this improves performance of theMEA.

As shown in FIG. 22 , an exemplary environment control device 10comprises an oxygen control electrolyzer cell 16 and a humidity controlelectrolyzer cell 17 configured around a conditioner chamber 62. An MEAair moving device 44, such as a fan, is configured to produce a flow ofprocess air 46, which is a flow of forced air, onto the anode of theoxygen control electrolyzer cell 16. As described herein, this greatlyincreases the efficiency of the oxygen control electrolyzer cell 16. Theair moving device 44 is coupled directly to the MEA and has closeproximity to the anode which may be important for improved efficiency.An MEA air moving device 44′, such as a fan, is configured between thehumidity control electrolyzer cell 17 and the conditioner chamber 62 toproduce a flow of process air 46′ onto the anode of the humidity controlelectrolyzer cell 17. This fan may be configured within the conditionerchamber with the MEA of the humidity control electrolyzer cell beingsealed against the conditioner chamber. Electrical contacts are coupledto each of the electrolyzer cells to provide a potential across theanode and cathode.

FIG. 23 shows a graph an enclosure temperature and humidity with andwithout a fan blowing onto the anode of a humidity control electrolyzer.The data shows that the humidity was reduced much more quickly when theelectrolyzer was operated with a fan blowing directly onto the MEA toproduce a flow of process air, or forced air, onto the anode of thehumidity control electrolyzer cell.

Referring now to FIGS. 24 and 25 , an exemplary oxygen controlelectrolyzer cell 16, is configured with an MEA air moving device 44,such as a fan, configured to produce a flow of process air 46 onto theanode 20 of the membrane electrode assembly 30. A water chamber 65 isconfigured around a forced air opening 48 to allow the forced air toimpinge directly onto the MEA or anode 20 of the MEA. A pervaporationlayer 66 that allows the transport of water therethrough, but preventsthe bulk flow of air, extends around the forced air opening to providewater or moisture to the MEA. A gasket 71 seals the pervaporation layerto the MEA. The flow of process air impinges directly onto the anodeside 21 of the MEA 30 and the cathode side 41 or cathode 40 of the MBAmay be sealed to a conditioner chamber, not shown. A data interface 86is configured to allow coupling of a data storage and/or a datatransmitter. Data related to the environment control device, such ashumidity level, oxygen level, temperature, MEA voltage potential and thelike may be stored and/or transferred to remote location. A fill port 63for receiving fluid, such as water for hydrating the ion conductingmedia, such as an ionomer is shown. The port may receive water or fluidfrom a condenser of the conditioner chamber, or it may be manuallyfilled, or attached to an automatic filing system, wherein when thewater chamber 65 drops below a certain level, a valve on the fill portfills the water chamber above a threshold level.

As shown in FIG. 26 , an exemplary environment control system 10 has adiscontinuous ionomer 76 between the anode 20 and cathode 40. Thediscontinuous ionomer has an anode ionomer layer 25, a cathode ionomerlayer 45 and a discontinuous ionomer layer 75. The discontinuous ionomerlayer will have less affinity to water, such as having a higherequivalent weight, as described herein, than the anode and/or cathodeionomer layers. Water may build up on the cathode side of thediscontinuous ionomer layer thereby preventing water migration to theanode side, back diffusion. Note that the discontinuous layer may be onthe anode side, cathode side or sandwiched between the anode and cathodeionomer layers as shown. Since the discontinuous ionomer layer may havehigher resistance to proton flow, the thickness of the discontinuouslayer may less than the thickness of the anode and/or cathode ionomerlayers, as shown. Also shown in FIG. 26 are two air moving devices 96,96′, such as a fan 97. The air moving devices may be used to movemoisture to or from the surface of the membrane electrode assembly 30.On the cathode side 41, an air moving device may move an excess or highlevel of water from the surface, thereby reducing the moistureconcentration gradient through the membrane and reducing back diffusion.Likewise, on the anode side 21, the fan 97 may move dry air away fromthe anode to reduce the moisture gradient from the cathode to the anode.

As shown in FIG. 27 , an exemplary non-electrochemical humidity membraneassembly 13 has a non-electrochemical anode 200 and anon-electrochemical cathode 400 separated by a moisture transfermaterial 72. A power supply 225 is providing power to the anode andcathode that will cause the electrically conductive anodes and cathodesto heat. The cathode may comprise a composition that will heat to ahigher temperature than the anode for a given amount of current, therebydriving moisture from the anode side 21 to the cathode 41 of theassembly. In addition, the cathode may comprise a composition that isself-heat limited, wherein the composition expands to become lessconductive as it heats. For example, some carbons may expand due totemperature increase and this expansion may reduce the current flowtherethrough to produce a self-temperature limiting composition. Inaddition, the anode and cathode may be configured over substantially theentire anode and cathode surface or be configured in a pattern, such asa grip pattern to increase absorption and desorption rates of water. Themoisture transfer material may comprise an ion exchange medium 25, 45and may comprise a back diffusion ionomer 75. Alternatively, themoisture transfer material may comprise a material having a highmoisture affinity, such as a material having high moisture vaportransmission rates including, but not limited to, urethane, hydrogels,silicone and the like.

As shown in FIGS. 28 and 29 , the cathode side 41 of an exemplarynon-electrochemical humidity membrane assembly 13 has anon-electrochemical cathode 400 that comprises a discontinuousconductive pattern. Note that the conductive pattern may be configuredon a membrane electrode assembly, as described herein, and anelectrochemical portion of the electrode, anode or cathode, may beconfigured in the areas between the pattern. The a non-electrochemicalportion of the electrode may be used to heat the electrode and drive offmoisture or to increase reaction rates.

Fluid communication, as used herein, means that gasses can flow to andfrom the two items described to be in fluid communication. For example,the cathode of an oxygen reduction electrolyzer cell may be in fluidcommunication with the oxygen control chamber, wherein the reactionproducts from the anode can freely flow into the oxygen control chamber.

The electrochemical cells, 12 shown in the figures may run aselectrolyzer cells, as described herein that perform electrolysis ofwater, wherein water is broken down on the anode into protons and oxygenand reformed on the cathode with the protons and oxygen.

The electrochemical cells can be operated at higher potentials toproduce ozone, which may be used to clean and disinfect the enclosure.

When an electrochemical cell is operated at a potential above 1.2 volts,electrolysis of water will occur and when operated above 2.08 volts,ozone may be produced.

Dehumidification device, as used herein, is a device that reduces thehumidity level or RH and includes, but is not limited to, a desiccant ordesiccator employing a desiccant, a condenser and a humidity reductionelectrolyzer cell.

It will be apparent to those skilled in the art that variousmodifications, combinations and variations can be made in the presentinvention without departing from the spirit or scope of the invention.Specific embodiments, features and elements described herein may bemodified, and/or combined in any suitable manner. Thus, it is intendedthat the present invention cover the modifications, combinations andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A humidity control electrolyzer cell comprising;a) an ion exchange medium; b) an anode; c) a cathode; wherein the anodeand cathode are configured on opposing sides of the ion exchange medium;wherein the ion exchange medium comprises an anion conducting ionomer,wherein the ion exchange medium is a discontinuous ionomer having adiscontinuous ionomer layer; wherein the discontinuous ionomer isconfigured between the anode and cathode; and wherein the discontinuousionomer has an anode ionomer layer, a cathode ionomer layer and adiscontinuous layer configured between the anode ionomer layer and thecathode ionomer layer.
 2. The humidity control electrolyzer cell ofclaim 1, wherein the ion exchange medium comprises an anion conductingionomer comprising quaternary ammonium functional groups.
 3. Thehumidity control electrolyzer cell of claim 1, wherein the discontinuouslayer has a higher equivalent that the remaining portion of thediscontinuous ionomer by at least 20%.
 4. The humidity controlelectrolyzer cell of claim 1, wherein the discontinuous ionomer layerhas a higher equivalent that the remaining portion of the discontinuousionomer by at least 35%.
 5. The humidity control electrolyzer cell ofclaim 1, wherein the discontinuous ionomer has thickness of no more than50 microns.
 6. The humidity control electrolyzer cell of claim 1,wherein the anion conducting polymer comprises: a backbone selected fromthe group consisting of: poly(arylene), poly(phenylene) andpoly(styrene); and an alkyl or piperidine side chain configured betweena functional group and a backbone of the anion conducting polymer. 7.The humidity control electrolyzer cell of claim 1, wherein the ionexchange medium is a composite ion exchange medium comprising a supportmaterial attached to the anion conducting polymer.
 8. The environmentcontrol system of claim 1, wherein the support material has a porosityof 55% to 90%.
 9. The environment control system of claim 8, wherein thesupport material comprises expanded polytetrafluoroethylene.
 10. Thehumidity control electrolyzer cell of claim 1, further comprising an airmoving device configured to move moisture from the surface of the anode.11. The humidity control electrolyzer cell of claim 1, wherein the ionexchange medium comprises an anion conducting ionomer comprisingphosphonium groups functional groups.
 12. The humidity controlelectrolyzer cell of claim 11, further comprising an air moving deviceconfigured to move moisture from the surface of the anode.
 13. Thehumidity control electrolyzer cell of claim 1, wherein the anionconducting polymer comprises alkyl or a piperidine side chain configuredbetween a functional group and a backbone of the anion conductingpolymer.
 14. The humidity control electrolyzer cell of claim 13, furthercomprising an air moving device configured to move moisture from thesurface of the anode.